SOLID-STATE REACTIONS OF ZEOLITES

The principle of preparation of modified zeolites by solid-state reaction is illustrated using simple systems such as mixtures of alkaline, alkaline earth or lanthanum chlorides and ammonium or hydrogen forms of zeolites. The advantages of this approach are discussed. Solid-state reaction is an attractive route to preparation of acidic or bifunctional catalysts. Finally, it is shown that solid-state modification is also possible using the as-synthesized sodium forms, for instance for an ion exchange with mono-, bi- and trivalent cations, which is investigated by IR, Na-23 MAS NMR, TPE and, in the case of FeCl2, additionally with Mossbauer spectroscopy.